0:00:06.761,0:00:09.132
The area surrounding the North Pole

0:00:09.132,0:00:14.052
may seem like a frozen and desolate[br]environment where nothing ever changes.

0:00:14.052,0:00:19.006
But it is actually a complex [br]and finely balanced natural system,

0:00:19.006,0:00:23.306
and its extreme location [br]makes it vulnerable to feedback processes

0:00:23.306,0:00:27.068
that can magnify even tiny changes[br]in the atmosphere.

0:00:27.068,0:00:32.282
In fact, scientists often describe [br]the Arctic as the canary in the coal mine

0:00:32.282,0:00:36.260
when it comes to predicting the impact[br]of climate change.

0:00:36.260,0:00:39.703
One major type of climate feedback[br]involves reflectivity.

0:00:39.703,0:00:41.946
White surfaces, like snow and ice,

0:00:41.946,0:00:46.027
are very effective at reflecting[br]the sun's energy back into space,

0:00:46.027,0:00:51.109
while darker land and water surfaces[br]absorb much more incoming sunlight.

0:00:51.109,0:00:55.094
When the Arctic warms just a little,[br]some of the snow and ice melts,

0:00:55.094,0:00:58.111
exposing the ground and ocean underneath.

0:00:58.111,0:01:01.966
The increased heat absorbed by[br]these surfaces causes even more melting,

0:01:01.966,0:01:03.605
and so on.

0:01:03.605,0:01:07.111
And although the current situation[br]in the Arctic follows the warming pattern,

0:01:07.111,0:01:09.365
the opposite is also possible.

0:01:09.365,0:01:12.607
A small drop in temperatures[br]would cause more freezing,

0:01:12.607,0:01:15.942
increasing the amount [br]of reflective snow and ice.

0:01:15.942,0:01:18.484
This would result in less sunlight [br]being absorbed,

0:01:18.484,0:01:22.757
and lead to a cycle of cooling,[br]as in previous ice ages.

0:01:22.757,0:01:26.634
Arctic sea ice is also responsible[br]for another feedback mechanism

0:01:26.634,0:01:28.271
through insulation.

0:01:28.271,0:01:30.206
By forming a layer on the ocean's surface,

0:01:30.206,0:01:33.446
the ice acts as a buffer between[br]the frigid arctic air

0:01:33.446,0:01:36.432
and the relatively [br]warmer water underneath.

0:01:36.432,0:01:39.450
But when it thins, breaks, [br]or melts in any spot,

0:01:39.450,0:01:41.642
heat escapes from the ocean,

0:01:41.642,0:01:45.720
warming the atmosphere [br]and causing more ice to melt in turn.

0:01:45.720,0:01:48.961
Both of these are examples[br]of positive feedback loops,

0:01:48.961,0:01:50.791
not because they do something good,

0:01:50.791,0:01:54.905
but because the initial change [br]is amplified in the same direction.

0:01:54.905,0:01:57.250
A negative feedback loop,[br]on the other hand,

0:01:57.250,0:01:59.701
is when the initial change[br]leads to effects

0:01:59.701,0:02:02.289
that work in the opposite direction.

0:02:02.289,0:02:05.276
Melting ice also causes [br]a type of negative feedback

0:02:05.276,0:02:08.367
by releasing moisture into the atmosphere.

0:02:08.367,0:02:12.119
This increases the amount and thickness[br]of clouds present,

0:02:12.119,0:02:15.626
which can cool the atmosphere[br]by blocking more sunlight.

0:02:15.626,0:02:18.077
But this negative feedback loop[br]is short-lived,

0:02:18.077,0:02:20.441
due to the brief Arctic summers.

0:02:20.441,0:02:22.824
For the rest of the year, [br]when sunlight is scarce,

0:02:22.824,0:02:24.649
the increased moisture and clouds

0:02:24.649,0:02:28.325
actually warm the surface[br]by trapping the Earth's heat,

0:02:28.325,0:02:32.491
turning the feedback loop positive[br]for all but a couple of months.

0:02:32.491,0:02:35.509
While negative feedback loops[br]encourage stability

0:02:35.509,0:02:38.049
by pushing a system towards equilibrium,

0:02:38.049,0:02:43.990
positive feedback loops destabilize it[br]by enabling larger and larger deviations.

0:02:43.990,0:02:47.083
And the recently increased impact[br]of positive feedbacks

0:02:47.083,0:02:50.387
may have consequences [br]far beyond the Arctic.

0:02:50.387,0:02:51.706
On a warming planet,

0:02:51.706,0:02:57.072
these feedbacks ensure that the North Pole[br]warms at a faster rate than the equator.

0:02:57.072,0:03:00.058
The reduced temperature differences[br]between the two regions

0:03:00.058,0:03:02.662
may lead to slower jet stream winds

0:03:02.662,0:03:06.936
and less linear atmospheric circulation[br]in the middle latitudes,

0:03:06.936,0:03:09.374
where most of the world's [br]population lives.

0:03:09.374,0:03:12.301
Many scientists are concerned[br]that shifts in weather patterns

0:03:12.301,0:03:14.959
will last longer and be more extreme,

0:03:14.959,0:03:18.912
with short term fluctuations becoming[br]persistent cold snaps,

0:03:18.912,0:03:22.539
heat waves, droughts and floods.

0:03:22.539,0:03:25.883
So the Arctic sensitivity doesn't just[br]serve as an early warning alarm

0:03:25.883,0:03:28.418
for climate change [br]for the rest of the planet.

0:03:28.418,0:03:32.593
Its feedback loops can affect us[br]in much more direct and immediate ways.

0:03:32.593,0:03:34.654
As climate scientists often warn,

0:03:34.654,0:03:38.447
what happens in the Arctic[br]doesn't always stay in the Arctic.